递归并找到最大数量

Question

So I am trying to use recursion to find the largest number in my program. I have to import one file into the other.

Here is the code I have so far:

def find_largest():
    numlist = [0]
    if numlist == 1:
       return numlist[0]
    else:
       m = find_largest(numlist[0])
       return m if m > numlist[0] else numlist[0]

find_largest()

That is the file calling the recursion. This is the main that will import it and establish the list.

import Collins_find_largest #file name to be imported

def main():
    number_list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

    print('List of numbers:\n', number_list, sep ='')

    print("largest Number in the list is: ", \
      Collins_find_largest.find_largest(number_list))

main()

When I run my code it comes back saying line m=find_largest(numlist[0]) takes 0 positional arguments but 1 was given.

Help Please!

Answer 1

You're missing a parameter in your function:

def find_largest(numlist=None):
    numlist = numlist or [0]
    if numlist == 1:
       return numlist[0]
    else:
       m = find_largest(numlist[0])
       return m if m > numlist[0] else numlist[0]

Answer 2

There are a few issues with your code, mainly you are missing num_list as a parameter:

def find_largest(num_list):
    if len(num_list) == 1:
        return num_list[0]
    else:
        m = find_largest(num_list[1:])
        return m if m > num_list[0] else num_list[0]


result = find_largest([1, 2, 3, 4])
print(result)

Output

4

Second when checking for the length of a list use len , finally you need to make the recursive call on the rest of the list ( num_list[1:] ).